This article explores the role of social media in athlete activism and sport commodification through the case studies of two elite multiracial athletes who represent Japan, professional tennis player Naomi Osaka and professional basketball player Rui Hachimura. Osaka’s mother is Japanese and her father is Haitian-American, whereas Hachimura’s mother is Japanese and his father is Beninese. Employing critical discourse analysis of Twitter and Instagram, we ask: How do they use social media to amplify their voices and advocacy for race and ethnicity? How do their athlete activism and multiracial identity appeal to fans and sponsors? We argue that social media lend them various ways for resistance through defying monoracial labeling and racialized sport stereotypes, manifesting their multiracial identity, speaking up against social justice issues, and affiliating with certain sponsors. We demonstrate how their “silent activism” is subtle, situated in everyday life, and not antithetical to the commodification of their (athlete-activist) image.